10 terrifying facts from Under the Dome

Under the Dome, the self-funded, slickly-produced documentary from former CCTV investigative reporter Chai Jing that shines a spotlight on air pollution in China, was pulled from Chinese internet streaming sites on Saturday, after it had been watched around 200 million times on portals such as Youku and Sohu.

Chai spent a year interviewing heads of local environmental protection bureaus and Chinese environmentalists to learn about the causes of China's growing smog problem over the past decade. Talking TED-style to a studio audience, Chai reveals through the 104-minute documentary that the absence of environmental protection legislation, the failure to implement existing rules and the general public’s lack of awareness in regard to reducing their carbon footprint have all contributed to the heavily polluted skies.

1. 500,000 people die of air pollution every year in China

This whopping figure comes from the former Minister of Health, Chen Zhu, who claimed in a 2013 article in medical journal The Lancetthat the estimated number of premature deaths due to air pollution in China is between 350,000-500,000.

In Under the Dome, Chai Jing quotes an interview with Professor He Xingzhou, author of A Survey of the Relationship Between Air Pollution and Cause of Death for 26 Chinese Cities, who has been researching air pollution in China for over 30 years. His work determined that the rise of air pollution levels in China correlated directly with the mortality rate as a result of lung cancer in 26 Chinese cities between 1976-1981.

Or, as Professor He puts it in the film, 'the rate of death from lung cancer is higher in cities with more air pollution; a city’s level of air pollution is positively correlated with lung cancer death rates.'

2. Beijing's daily PM 2.5 level is five times that of China’s average

This chart shows the maximum recommended daily limits of PM2.5 concentration given by, (from left) the World Trade Organisation, the USA, Europe and China.

The far right column shows the amount of PM 2.5 in the air in Beijing on the average 24 hour period of Chai Jing's experiment with an air filter. If not wearing any protection, people in China's capital city would have breathed in 305.91 micrograms of PM 2.5 in every cubic metre, which is almost five times the amount recommended as the maximum by the Chinese government. It's almost 12 times the amount recommended by the WTO.

3. There are 15 types of carcinogens found in China's PM2.5

Chai carried a PM 2.5 sampling pump around Beijing with her for 24 hours and asked Dr Xinghua Qiu of Peking University to test the results. The test discovered 15 types of carcinogens in the sampling pump, including one of the world’s strongest - benzo[e]pyrene, which is listed as a category 3 carcinogen by the International Agency for Research on Carcinogens. Its amount was 14 times the 'acceptable' amount recommended in China's air quality standards.

4. Hebei province is China's biggest burner of coal

A surprise to those who think of Shanxi province as China’s capital of coal, according to Professor Hao Jiming of Tsinghua University, 3.6 billion tonnes of coal were burnt in China in 2013. 300 million of those tonnes came just from Hebei Province, with the bulk of that figure coming from the steel industry in one city alone, Tangshan (pictured above).

Professor Hao's figures also state that China ranks number one in the world rankings of coal producing countries, but based on these numbers, Hebei province alone would come in at number two, and Tangshan city at number three. The whole of the USA is number four.

5. Shanghai burns more coal than any other metropolitan city in China

Despite popular perception, it's not just China's industrial north darkening our skies. This chart shows the steel plants, cement factories and power plants in eastern China. In Jiangsu province, there is one power plant for every 30 kilometres, while the factories and plants around Greater Shanghai burn ten kilograms of coal for every square metre of the city. Just imagine how many kilograms of coal would fill up your flat on this basis.

6. In 2013, Hangzhou had more than 200 days of smog

According to the head of Hangzhou's Environmental Protection Bureau, the city holds the highest number of cars per person in China, with registration reports showing there is one car for every two people in the city. 40 percent of pollutants in Hangzhou come from vehicle emission. This resulted in only 164 non-polluted days in 2013.

7. Beijing's PM 2.5 reaches its peak at midnight

According to the above graph from the Chinese Academy of Sciences, it's the middle of the night when pollution is at its highest in Beijing. This is when the big rumbling trucks cart goods throughout the capital.

Beijing has limitations on trucks that can enter its ring roads, with only those deemed environmentally clean supposed to be allowed through (indicated by a green license sticker) but according to Under the Dome this isn't always implemented, especially if the truck is carrying everyday food essentials needed to keep Beijing from grinding to a halt.

8. PM 2.5 levels are 25 times higher in winter than summer

The main reason Chai gives here is that more coal is burnt in winter. When running out of quality coal, lignite - a poorer quality coal - will be burnt, which emits more carcinogens. Due to the large amount of consumption, high cost in cleaning the lignite and poor control in emissions, PM2.5 level rises more easily during this period.

9. Every hour, one tonne of pollution is emitted within Beijing's Sixth Ring Road

According to another of Chai's graphs, transport is the primary source of pollution in Beijing as driving is the default mode of commuting for more than 34 percent of Beijingers. As a comparison, Chai notes that this figure is only 6 percent in Tokyo. According to a survey, nearly half of Beijing's residents would use a car if they needed to travel less than 5km, while 7 percent of Beijingers would still drive if the journey was less than 1km.

10. Only one percent of environmental disputes go to court in China

According to Under the Dome, this is because NGOs in China don't have the right to file a legal claim or be a legal entity in a lawsuit, something which is written into the Civil Procedure Act.

However, a new environmental law was brought in on January 1 this year which claims that as long as an organisation has been involved in environmental protection service for five years, without any criminal records or complaints, they have the right to act as an entity in a lawsuit. More than 700 environmental organisations now have such a right and have started testing this amendment to the law, although sadly it's too early to see any results.